Savior Mask

Izumo wearing a Savior Mask

The Savior Mask (選ばれし者 (セイバー) の仮面 Seibā no Kamen), an invention built and developed by Michael Gedōin, can force a demon to possess and remain in a host, regardless of compatibility. It is first used on Izumo Kamiki when it becomes clear that the Nine-Tailed Fox Spirit's possession of her is not taking hold. Gedōin later uses one of a slightly different design on himself and is possessed by a Necrophager.